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Rab7 regulates primary cilia disassembly through cilia excision.
Guang Wang1,2, Huai-Bin Hu1, Yan Chang1,3
1State Key Laboratory of Proteomics, National Center of Biomedical Analysis, Beijing, China.
The Journal of Cell Biology
|October 18, 2019
Summary
Rab7 regulates primary cilia disassembly by controlling actin polymerization for cilia ectocytosis. Depleting Rab7 inhibits cilia resorption and promotes cilia growth, revealing its essential role in cilia dynamics.
Area of Science:
- Cell Biology
- Molecular Biology
- Organelle Biology
Background:
- Primary cilia are crucial sensory organelles involved in cell signaling.
- Cilia assembly and disassembly are dynamic processes essential for their function.
- The molecular mechanisms regulating cilia disassembly are not fully understood.
Purpose of the Study:
- To identify novel regulators of primary cilia disassembly.
- To elucidate the role of the small GTPase Rab7 in cilia dynamics.
- To investigate the mechanism by which Rab7 controls cilia disassembly.
Main Methods:
- Depletion of Rab7 using knockdown techniques.
- Induction of ciliogenesis and cilia elongation.
- Assessment of serum-induced ciliary resorption.
- Analysis of cilia tip excision (cilia ectocytosis).
- Investigation of F-actin polymerization at cilia tips.
Main Results:
- Rab7 depletion induced spontaneous ciliogenesis and promoted cilia elongation.
- Knockdown of Rab7 blocked serum-induced ciliary resorption.
- Rab7 is essential for cilia disassembly, requiring active Rab7.
- Rab7 depletion suppressed cilia ectocytosis.
- Failure of F-actin polymerization at excision sites impaired cilia ectocytosis upon Rab7 depletion.
Conclusions:
- Rab7 is a novel regulator of primary cilia disassembly.
- Rab7 controls cilia ectocytosis through the regulation of intraciliary F-actin polymerization.
- Rab7 plays a critical role in the dynamic regulation of cilia assembly and disassembly.
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